Plate and fin heat exchanger



Feb- 21, 1967 R. l.. CAMPBELL ETAL 3,305,010

` PLATE AND FIN HEAT EXCHANGER Filed April 13, 1965 2 Sheets-Sheet l TC cgn g LFC-u l 1-:

ECC RE; f E* nr 1r *u Cl? INVENTORS 0 7 L CHNPEL ew@ P. ffrfe FE- 4 BY Feb- 21, 1967 R. L. CAMPBELL ETAL 3,305,010

PLATE AND FIN HEAT EXCHANGER Filed April 13, 1965 2 Sheets-Sheet 2 United States Patent O 3,305,010 PLATE AND FIN HEAT EXCHANGER Robert L. Campbell and Gene P. Deeter, Dayton,rhio, assignors to United Aircraft Products, Inc., Dayton, Ohio, a corporation of Ohio Filed Apr. 13, 1965, Ser. No. 447,753

Claims. (Cl. 165-166) This invention relates to plate and 1in heat exchangers,

and particularly to a new construction therefor providing for more efficient operation, that is, a construction lighter heat transfer surface, in heat exchangers of `high n density. y

Still another object of the invention is to provide a-construction characterized by a unique manifold design wherein the primary surface fin area extends into the manifold area in a manner to obviate flow blocking and high tiow restrictions.

Other objects and structural details of the invention will appearfrom the following description, when read in connection with the accompanying drawings, wherein:

FIG. 1 is a view in side elevation o f a plate and iin heat exchanger in accordance with the instant invention, a showing of plate and lin elements intermediate ends of the assembly being diagrammatically indicated; v

FIG. 2 is a top plan view of the assembly of FIG. 1, shown at a reduced scale;

FIG. 3 is a fragmentary view in cross section, taken substantially along the line 3-3 of FIG. 2, and enlarged relatively thereto;

FIG. 4 is a front end View of the device as shown FIG. 2; v

FIG. 5 is a fragmentary view in cross section, taken substantially along the line 5 5 of FIG. 2, and relatively enlarged;

FIG. 6 is a view in exploded isometric, showing detail of the construction and relationship of adjacent plate and tin elements;

FIG. 7 is a view partly diagrammatic and broken away showing the path of travel of a first liuid through the heat exchanger;

FIG. 8 is a View like FIG. 7 showing the path of iiow through the heat exchanger of a second fluid; and

FIG. 9 is a fragmentary view in longitudinal section taken substantially along the line 9-9 of FIG. 2 and enlarged relatively thereto.

Referring to the drawings, the illustrative device of the invention is of relatively large size, as shown in FIGS. y

1 and 2 for example, comprising a large number of plate and fin elements defining heat transfer surface commensurate with a large volume fluid flow. For convenience of illustration the device is shown in fragmentary form or at substantially reduced scale in other views. i

In a plate type heat exchanger in accordance with the instant invention the plate and iin elements are stacked in a superposed relation one upon another, with the assembly of parts being joined together in a brazing or like operation. At the top and bottom of the core comprised of the plate and tin elements are core sheets 11 and 12. In an alternating relation to one another and disposed between the core sheets are plate elements 13, hereinafter termed parting sheets, and fin elements. The latter are provided in two types 14 and 15, shown in FIG. 6, and which may be described as long and short elements respectively.

The core sheets 11 and 12 are flat, continuous surface parts rectangular in their original shape and having their corners cut off to deiine at each end angularly disposed faces converging to a point in the longitudinal axis of each sheet. Each core sheet has iny effect aA tapered nose at each end. The parting sheets 13 are made thin for good heat `transfer therethrough and have a conguration corresponding to that of the core sheets 11 and 12. In its tap-ered nose portions, however, each parting sheet is cut away to define through openings 16;. The 1in elements 14 have the same coniguration as core sheets 11 and 12 and parting sheets 13, but are somewhat narrower in their side to side dimension. Each of these also is made thin for good heat transfer therethrough and has a crimped or gathered shaped providing peaks and'valleys running lengthwise of the'element. There are no openings in the n elements 14 corresponding to the openings 16y in the parting sheets 13. The fin elements 15 are constructed like the elements 14 but are shorter in length, having no tapered nose portions at the ends thereof. As indicated in FIG. 7, in assembling a core structure the sheets 13 are placed in asuperposed alternating relation to the lin elements 14 and to the iin elements 15. Thus a superposed assembly is comprised of a parting sheet 13, a tin element 14 in next adjacent relation thereto, another parting 'sheet 13, a iin element 15, another parting sheet and so on.

Also comprised in the core assembly 4are spacer devices 17 associated with the long fin elements 14 and other spacer devices 18 associated with the short iin elements 1S. Thus the devices 17, which may be solid or have the channel-like configuration shown, extend longitudinally of the tin elements 14, one on each side thereof and are interposed asspacers between the marginal edges of-overlying and underlying parting sheets 13. Thus, the devices 17 complement the fin elements 14 in achieving a side to side dimension corresponding to the width of the parting sheets 13. Similarly/,the spacer devices 18 are disposed in la longitudinal complementary relation to the tin elements 15 at the sides thereof and are interposed as spacers between adjacent overlying and underlying parting sheets 13. The devices 18, however, yare long-er than the devices 17, each having a projected bent over finger portion 19 at one end. On the respective'sides of each iin element 15 the devices 18 are relatively inver! ed to -place their bent over ends 19 in a-projecting relation to respectively opposite ends of the tin element.

The angularity of the bent over ends 19 corresponds to that of the tapered nose ends of the sheets 13 and `elements 14. In assembling a core the parts are brought into a contacting relation in such manner that devices 17 contact and hold spaced apart a pair of parting sheets 13 While the devices 18 similarly contact and hold spaced apart a next adjacent pair of parting sheets 13. The ends 19 of the devices 18 are aligned with marginal edges of end faces of the sheets 13 in such manner as to close a space between adjacent'sheets 13 in a face at one end of the core assembly, and, since the devices 18 are relatively inverted at each iin element 15 then the closed portions at opposite ends of the core are `at diametrically opposite angular faces. Correspondingly in a space of one face closed by an end 19 a corresponding space in the same plane is open for ilow of a fluid into or out of the core. Such open area is, moreover, matched by a like opening in the same plane in the diametrically opposite face of the core at the other end.

Viewed from the front, or `from one end, therefore, as shown in FIG. 4, an assembled core presents angular faces 21 and 22 in each of'which is a series of entrance or exit openings 23. In the respective faces the openings 23 are vertically offset. Duct Work suitably placed against or fixed to the respective cre faces may thus be placed in communication with a part of the core interior independently of other duct means attached to the other core face to communicate with the openings therein.

Each opening 23 leads into or out of what may be considered a cham-ber 24 extending completely across the end of the core, as distinguished from the opening 23 which occupies only one face thereof` The chamber 24 is formed by overlying and underlying parting sheets 13 and by the end of a fin element 15 co-planar with the opening 23. Fluid within the chamber 24 has access to the iin element 15, on both sides thereof, and has access through the par-ting sheet openings 16 to the underside of an overlying fin element 14 and to the top side of an underlying fin element 14. Assuming a given opening 23 to function as an inlet, a iiuid entering a chamber 24 therethrough distributes itself throughout the chamber to be applied over the entire end of the iin element 15. The liuid flows longitudinally of such element on both sides thereof to the opposite end ofthe core where it enters another chamber 24 and discharges through an aligned opening 23. At the same time the fluid at the inlet end flows upward through an opening 16 in an overlying sheet 13 and flows downward through an opening 16 in an underlying sheet 13. There i-t contacts the underside and topside respectively of fin elements 14 and flows along these surfaces to the opposite end of the core. At such opposite end it moves into the aforementioned chamber 24 therein through parting sheet openings 16 and rejoins the first described stream of fluid in exiting through the aligned opening 23. The iin element 15 is in contacting heat conducting relation to overlying and underlying sheets 13 which are in turn in contacting, heat conducting relation to 1in elements 14. Accordingly, an indirect transfer of heat takes place through the fin element 15 through overlying and underlying sheets 13 to adjacent fin elements 14. At the same time, however, direct heat transfer takes place through the Walls of the iin elements 14. In this connection, above and below the described iiow passages are other like sets of passages in which a iiuid of different temperature may flow counter to the movement of the first described iiuid. The iin elements 14 are common to adjacent sets of passages with these fin elements accordingly serving as means for a direct transfer of heat between fluids of different temperature. The elements 14 and 15 represent, respectively, primary and secondary heat transfer surfaces.

The liow through the heat exchanger core is, as noted, counterfiow, the flow being substantially as indicated in FIGS. 7 and 8. Thus, as shown in FIG. 7 a first iiuid such as a gas enters the heat exchanger core through one end thereof at one of the angularly disposed faces. Distributing itself and iiowing longitudinally of the core in the manner above described the gas leaves the heat exchanger by way of the diametrically opposed face at the opposite end of the core. Similarly, as shown in FIG. 8, another fluid such as air enters the heat exchanger at the same end throughwhich the gas discharges, but in the other angularly disposed face. The air then flows reversely through the heat exchanger, counter to the flow of the gas, and exits through the first described end through the face other than the one admitting the gas. Within the heat exchanger the fluids have a relationship to one another and to the iin elements 14 and 15 substantially as indicated in FIGS. 3 and 5. In these views, which are fragmentary across sections through the heat exchanger core, shaded areas indicate the presence of gas While the unshaded areas indicate the presence of air. Thus in the uppermost part of FIG. 3 a fin element 15 is shown disposed in the air iiow stream. Air is present on both sides of the element 15 and is present also above and below adjacent parting sheets 13 (by virtue of having passed through openings 16 therein) where it is in Contact with CII one side only of respective iin elements 14. On the other side of these elements 14 gas is pres-ent for a direct transfer of heat through the fin surface. Gas also is present on both sides of the next adjacent iin element 15, and, beyond such iin element 15, on one side of the succeeding iin element 14. The iin elements 15 perform a function in maintaining a spaced relation between the fin elements 14 and serve also as indirect or secondary heat transfer means, conducting heat through contacted plates Or sheets 13 to companion fin elements 14.

The openings 23 and chambers 24 at the ends of the core provide a manifolding means which makes possible a high fin density with relatively low restriction and without fluid iiow blockage. The fluid in the chambers 24 has ready access to and is in communication with the underlying and overlying fin elements 14 and movement of the fiuid to and through the flow passages defined by the corrugations of the iin elements is unimpeded.

The ends of the iin elements 14 are closed to inhibit bypassing of the iiuids. This may be done in any suitable manner, as by depositing weld metal 25 at the ends `ofthe elements, as indicated in FIG. 4, whereby to close the face of the core at the location of the elements 14. According to another method the tips of elements 14 may be overlaid by strips having filler portions received between the undulating fins and united therewith in a brazing operation which may be the same operation joining together the several parts of the core.

What is claimed is:

1. A plate type heat exchanger assembly, including superposed stacked plate and fin elements, said plate elements defining liow paths occupied by said iin elements, said iin elements being arranged in sets of three with a middle iin of each set being short in relation to the other iins of the set to dene at least one end of said assembly at each set of said elements a chamber wherein introduced fluid has access to both sides of said middle lin and access to one side only of the said-other fin elements, a plate element being disposed between said middle iin and each of said other tins in heat conducting relation therebetween, adjacent sets of iins having said other fins in common, and manifolding means for introducing fluids of different temperature to opposite ends of said assembly to flow counter to one another through adjacent sets of fin elements, said other fin elements being in projecting relation to said middle iin element at each end thereof to define chambers for the entrance and exit of a fluid, said plate elements being formed to allow communication thereby between said chambers and said other tins on the said one sides thereof.

2. A plate type heat exchanger assembly constructed for the -counterflow of iiuids of different temperature, including a plurality of stacked iin elements comprised of alternating short and long elements, the latter projecting at each end beyond the former and having each end defining different angular faces, the ends of said long elements being closed, means for closing each side margin of said fin elements, certain of said means at the location of said short iin elements extendingacross an angular face at one end of the assembly, adjacent ones of said certain means being relatively inverted to leave at corresponding faces at opposite ends relatively offset openings, a iiuid being admitted to said assembly by way of a series of said openings in one face of said assembly at one end thereof and exhausting from'openings at a diametrically opposite face at the opposite end and a iiuid of different temperature being admitted to said assembly by way of a series of said openings in the other face of said assembly at the said opposite end and exhausting from openings at the other face at said one end, the fluids owing over said fin elements in counterflow through said assembly, and parting sheets between said fin elements, said sheets affording communication of the openings with the underside and topside of respective adjacent long fin elements to utilize said elements as direct heat transfer surface.

3. A plate type heat exchanger according to claim 2, characterized in that said parting sheets are shaped in correspondence with the shape of said long elements and in the portions projected relatively to said short n elements are cut away to provide the described communication.

4. A plate type heat exchanger assembly constructed for the counterow of uids of different temperature, including a plurality of stacked fin elements comprised of alternating short and long elements, the latter projecting at each end beyond the former and having their ends closed, parting sheets between said n elements coextensive in length and aligned with said long fin elements, marginal spacer devices interposed between adjacent pairs of parting sheets along the sides of said fm elements, certain spacer devices at locations of said short fm elements being bent over and extending partly across one end of the assembly, adjacent ones of said certain devices being relatively inverted to leave at each end of the assembly adjacent openings which are laterally and vertically offset from one another, and openings in the portions of said parting sheets projected relatively to said short iin elements whereby a fluid introduced into an opening at one end of the assembly may flow through the assembly in contact with both sides of a short n and in contact with overlying and underlying surfaces only of adjacent long fin elements and may discharge through a corresponding opening at the opposite end of the assembly.

5. A plate type heat exchanger assembly constructed for the counterflow of tluids of dilferent temperature, including a plurality of stacked fin elements comprised of alternating short and long elements, the latter projecting at each end beyond the former, the ends of said long elements being closed, other means for closing each side margin of said fin elements, portions of certain of said means at the location of said short fin elements extending angularly partly across one end of the assembly, adjacent ones of said certain means being relatively inverted to leave at each end relatively offset openings with the openings at opposite ends being reversely disposed, a fluid being admitted to said assembly by way of a vertical series of said openings in one side face of said assembly at one end thereof and exhausting from openings at a diametrically opposite face at the opposite end and a fluid of different temperature being admitted to said assembly by way of a series of said openings in the other face of said assembly at the said opposite end and exhausting from openings at the other face at said one end, fluids owing over said n elements in counterflow through said assembly, the length of said long elements relative to said short elements being such to define with the extending portions of said certain of said closing means relatively large chambers in which entering fluid may distribute itself for substantially uniform flow through the ow passages communicating with said chambers, and parting sheets between said n elements, said sheets being formed to communicate said openings with said chambers and thereby with the underside and topside of respective adjacent long iin elements to utilize said elements as direct heat transfer surface.

References Cited by the Examiner UNITED STATES PATENTS 2,288,061 6/1942 Arnold 165-157 X 2,566,310 9/1951 Burns et al. 165-157 X 2,875,986 `3/1959 Holm 16S-166 X 3,165,152 1/1965 Jones 16S-166 3,198,248 8/1965 Stack 165-166 3,241,607 3/1966 Rutledge 16S-166 ROBERT A. OLEARY, Primary Examiner. T. W, STREULE, Assistant Examiner. 

1. A PLATE TYPE HEAT EXCHANGER ASSEMBLY, INCLUDING SUPERPOSED STACKED PLATE AND FIN ELEMENTS, SAID PLATE ELEMENTS DEFINING FLOW PATHS OCCUPIED BY SAID FIN ELEMENTS, SAID FIN ELEMENTS BEING ARRANGED IN SETS OF THREE WITH A MIDDLE FIN OF EACH SET BEING SHORT IN RELATION TO THE OTHER FINS OF THE SET TO DEFINE AT LEAST ONE END OF SAID ASSEMBLY AT EACH SET OF SAID ELEMENTS A CHAMBER WHEREIN INTRODUCED FLUID HAS ACCESS TO BOTH SIDES OF SAID MIDDLE FIN AND ACCESS TO ONE SIDE ONLY OF THE SAID OTHER FIN ELEMENTS, A PLATE ELEMENT BEING DISPOSED BETWEEN SAID MIDDLE FIN AND EACH OF SAID OTHER FINS IN HEAT CONDUCTING RELATION THEREBETWEEN, ADJACENT SETS OF FINS HAVING SAID OTHER FINS IN COMMON, AND MANIFOLDING MEANS FOR INTRODUCING FLUIDS OF DIFFERENT TEMPERATURE TO OPPOSITE ENDS OF SAID ASSEMBLY TO FLOW COUNTER TO ONE ANOTHER THROUGH ADJACENT SETS OF FIN ELEMENTS, SAID OTHER FIN ELEMENTS BEING IN PROJECTING RELATION TO SAID MIDDLE FIN ELEMENT AT EACH END THEREOF TO DEFINE CHAMBERS FOR THE ENTRANCE AND EXIT OF A FLUID, SAID PLATE ELEMENTS BEING FORMED TO ALLOW COMMUNICATION THEREBY BETWEEN SAID CHAMBERS AND SAID OTHER FINS ON THE SAID ONE SIDES THEREOF. 